Optical interferometry is a technique in which two separate light pulses, a sensing pulse and a reference pulse, are generated and interfere with each other. When optical interferometry is used for fiber optic sensing applications, the sensing and reference pulses are at least partially reflected back towards an optical receiver. For example, optical interferometry may be performed by directing the sensing and reference pulses along an optical fiber that comprises fiber Bragg gratings, which partially reflect the pulses back towards an optical receiver at which interference is observed. The nature of the interference observed at the optical receiver provides information on the optical path length the pulses traveled, which in turn provides information on parameters such as the strain the optical fiber experienced.
The circuitry that generates, modulates, and receives the sensing and reference pulses is typically contained within a device called an optical interrogator. There exists a continued desire to advance and improve technology used in optical interrogators.